Life Sciences (GATE)

Correct answer. A is correct and R is incorrect. Dimethyl sulfoxide (DMSO) is used as a cryopreservant for mammalian cell cultures to protect cells from ice crystal induced mechanical injury. It protects cells by preventing crystallisation of water.

Correct answer. Structural Classification of Proteins (SCOP) database and CATH Protein Structure Classification are examples of derived protein structure databases.

Correct answer.
AUGUSTUS is a program that predicts genes in eukaryotic genomic sequences.
mGene is a computational tool for the genome-wide prediction of protein coding genes from eukaryotic DNA sequences.

Pyrrolidine-2-carboxylic acid is IUPAC name of proline.

Correct answer. Correct sequence of signal transduction pathway is Hormone → 7 TM receptor → G protein → cAMP → PKA.
In the G protein associated signal cascade system, binding of hormone to a cell surface receptor, like the 7TM (a 7 transmembrane alpha helices) which is a part of G protein. This will activate production of second messengers like cAMP by the enzyme adenylate cyclase. The cAMP in turn binds and activates downstream signal proteins line cAMP dependent protein kinase A (PKA).

Correct answer. Both are false statements. Synteny refers to gene duplication from a common ancestor. This is the condition in which two or more gene loci are present on the same chromosome. During evolution, rearrangements may cause the loss of synteny, else it will be retained. Translocations can cause gain of synteny. In zinc finger proteins, the amino acid residues that coordinate zinc are cys and his. Zinc fingers coordinate zinc ions with a combination of cysteine and histidine residues. They can be classified by the type and order of these zinc coordinating residues (e.g. cys2his2, cys4, and cys6).

The cryptochrome and the BLUF-proteins use flavin adenine dinucleotide (FAD) as chromophores.

Correct answer. Both are false statements.
Heat-inactivation (heating to 56°C for 30 minutes) of serum is done to inactivate complement, a group of proteins present in sera that are part of the immune response.
A nude mouse is a laboratory mouse from a strain with a genetic mutation that causes a deteriorated or absent thymus, resulting in an inhibited immune system due to a greatly reduced number of T cells.

Correct answer.
Pancuronium is a non-depolarising neuromuscular blocking agent used to facilitate intubation and relax skeletal muscles.
Tubocurarine is a toxic alkaloid and skeletal muscle relaxant in the category of non-depolarising neuromuscular-blocking drugs, used adjunctively in anesthesia to provide skeletal muscle relaxation during surgery or mechanical ventilation.

Correct answer.
Single letter code for glutamine is Q.
Single letter code for lysine is K.
Single letter code for tryptophan is W.
Single letter code for tyrosine is Y.

It is the correct answer. A and R both are correct and R is the correct explanation of A.
Gram-positive bacteria are generally resistant to complement-mediated lysis because thick peptidoglycan layer prevents insertion of membrane attack complex into the inner membrane.

Phrap is a widely used program for DNA sequence assembly. It is a DNA sequence assembler and finishing tools from the UW Genome Center.

Correct answer.
The cell membrane (also known as the plasma membrane or cytoplasmic membrane) is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells
Ribosomes are small, electron-dense particles not enclosed in membrane and are located in the cytosol. Ribosomes are involved in protein synthesis.
Inclusion bodies are the transitory residents of the cytoplasm not involved in cell metabolism and do not survive cell division. They comprise mainly accumulated metabolites, lipid droplets and pigments and are sporadically distributed in body cells.
An endospore is dormant, tough, and non-reproductive structures produced by certain bacteria from the Firmicute phylum, that help bacteria survive in adverse conditions.

 Belladonna contains the chemical substance atropine which indeed affects the pupils in the manner described.
Paclitaxel is a mitotic inhibitor used in cancer chemotherapy. It was discovered in a US National Cancer Institute program at the Research Triangle Institute in 1967 when Monroe E. Wall and Mansukh C. Wani isolated it from the bark of the Pacific yew tree, Taxus brevifolia and named it taxol.

Correct answer. A is correct and R is incorrect. Hyposecretion of somatotropin hormone (STH) causes Simond’s disease. STH is secreted by anterior lobe of pitutary.